West Nile virus activity--eastern United States, 2001.

In 2000, ArboNET, an enhanced human and animal surveillance system designed to monitor the geographic spread of West Nile virus (WNV) in the United States and to identify areas at increased risk for human infections with WNV, detected WNV activity in the District of Columbia and 12 states. This system, first implemented in the District of Columbia and 20 states along the Atlantic and Gulf coasts, was later expanded throughout the continental United States. This report summarizes ArboNET data from January 1 through July 25, 2001, which documents epizootic WNV activity in the southeast and indicates the need for widespread implementation of WNV prevention activities.